CVE-2023-36835

Junos OS: QFX10000 Series: All traffic will be dropped after a specific valid IP packet has been received which needs to be routed over a VXLAN tunnel

HIGH

7.5

CVSS Score

Published: July 14, 2023 at 05:11 PM UTC

Updated: June 17, 2026 at 06:07 AM UTC

5 products affected across 2 vendorsJunosQfx10008Qfx10016

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Severity

HIGH7.5

Exploit prediction

EPSS 0.6%

SSVC

No known exploit

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on QFX10000 Series allows a network based attacker to cause a Denial of Service (DoS). If a specific valid IP packet is received and that packet needs to be routed over a VXLAN tunnel, this will result in a PFE wedge condition due to which traffic gets impacted. As this is not a crash and restart scenario, this condition will persist until the system is rebooted to recover. This issue affects Juniper Networks Junos OS on QFX10000: 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S5; 21.1 versions prior to 21.1R3-S5; 21.2 versions prior to 21.2R3-S5; 21.3 versions prior to 21.3R3-S4; 21.4 versions prior to 21.4R3-S1; 22.1 versions prior to 22.1R3; 22.2 versions prior to 22.2R2; 22.3 versions prior to 22.3R1-S2, 22.3R2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

20.3 ≤ v < 20.3*20.4 ≤ v < 20.4R3-S521.1 ≤ v < 21.1R3-S521.2 ≤ v < 21.2R3-S521.3 ≤ v < 21.3R3-S421.4 ≤ v < 21.4R3-S122.1 ≤ v < 22.1R322.2 ≤ v < 22.2R222.3 ≤ v < 22.3R1-S222.3 ≤ v < 22.3R1-S2, 22.3R222.3 ≤ v < 22.3R220.3 20.3 r1 20.3 r1-s1 20.3 r1-s2 20.3 r2 20.3 r2-s1 20.3 r3 20.3 r3-s1 20.3 r3-s2 20.3 r3-s3 20.3 r3-s4 20.3 r3-s5 20.3 r3-s6 20.4 20.4 r1 20.4 r1-s1 20.4 r2 20.4 r2-s1 20.4 r2-s2 20.4 r3 20.4 r3-s1 20.4 r3-s2 20.4 r3-s3 20.4 r3-s4 21.1 21.1 r1 21.1 r1-s1 21.1 r2 21.1 r2-s1 21.1 r2-s2 21.1 r3 21.1 r3-s1 21.1 r3-s2 21.1 r3-s3 21.1 r3-s4 21.2 21.2 r1 21.2 r1-s1 21.2 r1-s2 21.2 r2 21.2 r2-s1 21.2 r2-s2 21.2 r3 21.2 r3-s1 21.2 r3-s2 21.2 r3-s3 21.2 r3-s4 21.3 21.3 r1 21.3 r1-s1 21.3 r1-s2 21.3 r2 21.3 r2-s1 21.3 r2-s2 21.3 r3 21.3 r3-s1 21.3 r3-s2 21.3 r3-s3 21.4 21.4 r1 21.4 r1-s1 21.4 r1-s2 21.4 r2 21.4 r2-s1 21.4 r2-s2 21.4 r3 22.1 22.1 r1 22.1 r1-s1 22.1 r1-s2 22.1 r2 22.1 r2-s1 22.1 r2-s2 22.2 22.2 r1 22.2 r1-s1 22.2 r1-s2 22.3 22.3 r1 22.3 r1-s1

Affected range stops below 20.3*, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.4R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.1R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.2R3-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.3R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.4R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.2R2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R1-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R1-S2, 22.3R2, so it looks safe — our inference, not a vendor statement

Affected range stops below 22.3R2, so it looks safe — our inference, not a vendor statement

juniper-qfx10002 (environment) · juniper-qfx10002-60c (environment) · juniper-qfx10008 (environment) · juniper-qfx10016 (environment)

Qfx10002 · Juniperdevice

80%

All versions

Qfx10002-60C · Juniperdevice

80%

All versions

Qfx10008 · Juniperdevice

80%

All versions

Qfx10016 · Juniperdevice

80%

All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

https://supportportal.juniper.net/JSA71642

References (1)

Vendor Advisory

Source: [email protected]

https://supportportal.juniper.net/JSA71642

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHjuniper

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: NONE
Integrity: NONE
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-754

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